Eradicating Houttuynia Cordata Chameleon “Fish Mint”

(Question)

I made the mistake of planting some “chameleon plant” a couple of years ago and it has absolutely taken over. I need to permanently eradicate it and spent a couple of hours today with my “loop weeder” which cuts the plant off just below the soil surface. I could not dig out the roots; they just go too deep. If I continue to cut off new plants as they emerge, will this eventually die from lack of chlorophyll to the leaves?? Or do I have to dig up all of the roots (I have no idea how I would manage that; I’m not retired, work 60 hour weeks and have very little time to spend in the garden.) Many thanks in advance!

(Answer)

Thank you for contacting Toronto Master Gardeners.

Although Houttuynia Cordata is sold as an ornamental plant, it is an invasive species. It spreads underground by very long rhizomes. Cutting rhizomes encourage them to grow more and more; even a small bit of root will spread.

You chose a good approach to manage this bad plant. If you keep cutting off new leaves as they emerge the continual defoliation will exhaust the root reserves and eventually kill the plant. Do not let the plants flower and set seed. Unfortunately, it could be very long. You have to dispose all cuttings in your garbage and never compost them.

Black polyethylene mulch or landscape fabric can also be effective but only if no light is allowed to reach the soil or plants. The edges should be overlapped so that no plants can grow between the sheets towards the light. Care should also be taken that no holes are punched into the fabric allowing light to accidentally reach the plants. You can cover the plastic or fabric with bark or rock to make it more aesthetically pleasing.